Question:
What is the word "cons" and "pros" short for? I know what they mean but could you please tell me the whole word?

Answer:These come from Latin, but only one was a self-standing word on its own. Pro is a full word, and is also used as a prefix, meaning "for" or forward". (The same prepostion/adverb exists in Greek, both ancient and modern, as pros.)

But con is the English shortened form of the Latin word contra, meaning against, or opposed to. Pro is the Latin for "for," or "in favour of;" contra is simply the Latin preposition and adverb for "against."

There was another word in Latin, which we also borrow: con. This word means with, and is still used in that same way in English. All of these are commonly used as prefixes on verb roots in English:

contradict = speak againstcontra-indications = reasons not to do something

consent = have sense or meaning with, and thus agree withcongregate = gather with, gather togetherCon also takes the phonetic form of the verb it joins: communicate, collate, collect